Method of designing and fabricating patient-specific restorations from intra-oral scanning of a digital impression coping

ABSTRACT

Taking a digital implant or abutment level digital impression by means of intra-oral, computed tomography or other imaging method provides the restorative doctor and laboratory accurate and effective data for determining the implant position, angulation and locking feature orientation without a physical impression. Such data is correlated with a digital library to produce an output which enables design and fabrication of an accurate restorative device such as a prosthetic tooth or crown. In this way the time-consuming, costly and error prone mechanical replication of the relevant dental anatomy is obviated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/740,769, filed on Jan. 13, 2020, now U.S. Pat. No. 11,042,979, whichis a continuation of U.S. patent application Ser. No. 14/516,981, filedon Oct. 17, 2014, now U.S. Pat. No. 10,561,478, which is a continuationof U.S. patent application Ser. No. 12/800,784, filed on May 21, 2010,now U.S. Pat. No. 8,867,800, which claims priority to and the benefit ofU.S. Provisional Application No. 61/217,186, filed on May 27, 2009. Theentireties of each of these applications are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to the design and manufacture ofpatient-specific dental restorations. More specifically, the inventionherein relates to restorations such as implant abutments, screw-retainedcrowns, implant and abutment over-denture and temporary prostheses atthe implant and abutment level.

BACKGROUND DISCUSSION

Dental implants have become the preferred modern alternative forreplacing missing natural teeth. Typically, an implant abutment issecured into the underlying bone tissue terminating within thesurrounding gum tissue. Eventually, a dental restoration is secured tothe implant. The restoration must be designed to match the surroundingteeth in color, size, shape and orientation so that it looks andfunctions much as the predecessor natural tooth it replaces. However,because of potential variability in the precise position (angulation andvertical position) and locking orientation of the implant, the design ofthe restoration is also subject to substantial variability.

Conventionally, the restoration is designed by a laboratory using aphysical replication of the dental anatomy. This physical replication isobtained by affixing an impression coping, locked to the underlyingimplant or abutment and extending above the gum line among thesurrounding dental structure. Then the area is replicated using dentallaboratory techniques and a model is produced. The laboratory then usesthis model to design and fabricate the prosthetic restoration.Unfortunately, these various steps are time consuming, costly andpotentially error prone.

SUMMARY OF THE INVENTION

The present invention overcomes the noted deficiencies and disadvantagesof the prior art laboratory process. The invention herein entirelyobviates the need for a physical replication to be sent to a laboratoryto provide information for the design and fabrication of an implantrestoration. The invention comprises the following steps:

1. A digital impression coping is affixed to the implant or abutment(for an abutment level digital impression) by means of a screw or it isfriction retained. Digital impression copings for computed tomographyand related imaging methods are made from radiopaque materials.

2. The digital impression coping(s) and surrounding dental anatomy arethen imaged via intra-oral, computed tomography or other imagingtechnology including magnetic resonance imaging (MRI).

3. The scan of the digital impression coping(s) is correlated withreference impression digital impression coping(s) to determine theimplant(s) position, angulation and locking feature orientation.

4. A laboratory then utilizes a CAD program that uses the implant(s) orabutment(s) spatial relation to the patient's oral anatomy to designpatient-specific prosthetic restoration(s) and create the output file(s)required for its manufacture.

Taking a digital implant or abutment level digital impression by meansof intra-oral, computed tomography or other imaging method provides therestorative doctor and laboratory an accurate and effective means ofdetermining the implant position, angulation and locking featureorientation without a physical impression. This digital impression hasapplications including, but not limited to:

1. Designing and fabricating patient-specific restorations such asimplant abutments, screw-retained crowns, implant and abutment levelover-denture restorations and temporary prostheses at the implant andabutment level.

2. As a record of a patient's implant and anatomical spatial data on aspecific date.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned objects and advantages of the present invention, aswell as additional objects and advantages thereof, will be more fullyunderstood hereinafter as a result of a detailed description of apreferred embodiment when taken in conjunction with the followingdrawings in which:

FIG. 1 is a photograph of a patient's oral anatomy adjacent an implantto which a digital impression coping has been affixed and locked intoengagement;

FIG. 2 is a photograph of an intra-oral scanning process of thepatient's implant area of FIG. 1 ;

FIGS. 3A and 3B are images obtained by the scanning process of FIG. 2showing the precise vertical position, angular orientation and lockingengagement of the digital impression coping and adjacent dental anatomy;

FIG. 4 is an image similar to that of FIGS. 3A and 3B, but showing theoral anatomy with a restoration in place of the digital impressioncoping and positioned in engagement with the underlying implant ready toreceive a prosthetic tooth or crown based upon data derived from theoriginally scanned image; and

FIG. 5 is an image of the relevant anatomy showing placement of aprosthetic implant abutment, designed and fabricated by employing thepresent invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

This method of digital implant and abutment level impression taking issimilar to conventional methods, but the implant position, angulationand locking feature orientation are captured via intra-oral, computedtomography or other imaging methods instead of with physical impressionmedia. The basic components required to capture an implant or abutmentlevel digital impression and design a restoration from the digitalimpression are:

1. A digital impression coping of known dimension, for implant orabutment level, with a flat, radius, slot or other geometricallydistinct feature, or features, for determining the implant position,angulation and locking feature orientation.

2. An intra-oral, computed tomography or other imaging method that canrecord the digital impression coping(s) and oral anatomy with sufficientaccuracy.

3. A means of correlating the scan of the digital impression coping witha reference digital impression coping thereby deriving the implant(s)position, angulation and locking feature orientation.

4. CAD software to design the implant or abutment level restorations andcreate an output file(s) for additive or subtractive manufacture of theimplant or abutment level prosthetic restoration.

The paragraph 1 component is shown in FIG. 1 . As seen therein, adigital impression coping 22 has been affixed to the underlying implantin the oral cavity 20 in an area 24. The abutment is in lockingengagement with the implant so that its position and orientation (notethe flat area 23 at the upper end of the abutment) will provide precisedata in regard to the underlying implant. This data becomes evident in ascan of the area being taken as shown in FIG. 2 . A number of availableintra-oral scanners 26 are available for performing this step. One suchscanner, for example, is an IOS FastScan™ Digital Impression Systemshown in FIG. 2 . The resultant images 30, 32 and 34 are shown in FIGS.3A and 3B. These images represent the type of data that can beelectronically transmitted to a laboratory for the area 24 a.

Laboratory personnel maintain a digital library of impression copingsthat can be correlated to the scan data of the digital impression copingin the patient's mouth. Based upon the digital impression coping lengthand the location of the “orientating feature” on the upper end of thedigital impression coping, three additional types of information can beobtained, namely:

1. The angulation as determined by the angle of the digital impressioncoping 22 a;

2. The position of the implant restorative connection (i.e., itsposition with respect to the implant-level, or the abutment level andother important fixed points such as adjacent and opposing contacts);and

3. The locking feature orientation (i.e., where the orientating featureon the digital impression coping matches with a corresponding feature 23on the implant connection).

The laboratory personnel can then employ these data, derived both fromthe image and from their library, to utilize CAD software to create anoutput file 36 (see FIG. 4 ) of the prosthetic restoration 38 from whichthe physical restoration 40 is then fabricated and sent to the dentistor implant surgeon who mates it with the implant 25 (see FIG. 5 ).

Having thus disclosed a preferred embodiment of the invention, it willnow be apparent that variation from the described example, iscontemplated. By way of example, the image may be derived in ways notspecifically described herein and the digital impression coping may beconfigured with various alternative characteristics which alter the datafrom that specifically disclosed herein. Accordingly, the scope of theinvention herein is not necessarily limited to the specific embodimentdepicted, but only by the appended claims and their legal equivalents.

The invention claimed is:
 1. A method for designing and fabricating adental prosthetic restoration for mating with a dental implant installedin a patient without requiring a physical impression of the patient'soral cavity, the method comprising the steps of: a) mating a digitalimpression coping with said dental implant, said digital impressioncoping including at least one geometrically distinct feature fordetermining the position and angulation of the dental implant; b)scanning an image of said digital impression coping and adjacent dentalanatomy; c) removing said digital impression coping from said dentalimplant; d) using said scanned image and CAD software to design arestoration to mate directly with said dental implant including the stepof correlating said scanned image to a library of digital impressioncoping data; e) creating an output file for additive manufacturing ofthe restoration; and f) additively manufacturing the restoration.
 2. Themethod recited in claim 1 wherein the library of digital impressioncoping data is representative of a plurality of digital impressioncopings corresponding to dental implants of a plurality of differentmanufacturers.
 3. The method recited in claim 1 wherein step b)comprises the step of producing an oral cavity image which includes atleast adjacent and opposing teeth of said patient in relation to saiddental implant.
 4. The method recited in claim 1 wherein step b)comprises using an intra-oral imaging method to scan said image.
 5. Themethod recited in claim 1 wherein step b) comprises using magneticresonance imaging (MRI) method to scan said image.
 6. The method recitedin claim 1, further comprising the step of installing the restorationonto the dental implant in place of the digital impression coping.
 7. Amethod of designing a dental prosthetic restoration for mating with adental implant installed in a patient without requiring a physicalimpression of the patient's oral cavity, the method comprising the stepsof: a) affixing a digital impression coping to said dental implant, saiddigital impression coping including at least one geometrically distinctfeature for determining the position and angulation of the dentalimplant; b) scanning said digital impression coping; c) removing saiddigital impression coping from said dental implant; d) correlating saidscanning of said digital impression coping to a library of digitalimpression coping data; e) using CAD software to design a restoration tomate directly with said dental implant; f) creating an output file foradditive manufacturing of the restoration; and g) additivelymanufacturing the restoration.
 8. The method recited in claim 7 whereinthe library of digital impression coping data is representative of aplurality of digital impression copings corresponding to dental implantsof a plurality of different manufacturers.
 9. The method recited inclaim 7 wherein step b) comprises the step of producing an oral cavityimage which includes at least adjacent and opposing teeth of saidpatient in relation to said dental implant.
 10. The method recited inclaim 7 wherein step b) comprises using an intra-oral imaging method toscan said digital impression coping.
 11. The method recited in claim 7wherein step b) comprises using magnetic resonance imaging (MM) methodto scan said digital impression coping.
 12. The method recited in claim7, further comprising the step of installing the restoration onto thedental implant in place of the digital impression coping.
 13. A methodof designing and fabricating a dental prosthetic restoration for matingwith an implant abutment attached to an implant installed in a patientwithout requiring a physical impression of the patient's oral cavity,the method comprising the steps of: a) mating a digital impressioncoping with said abutment, said digital impression coping including atleast one geometrically distinct feature for determining the positionand angulation of the abutment; b) scanning an image of said digitalimpression coping and adjacent dental anatomy; c) removing said digitalimpression coping from said abutment; d) using said scanned image andCAD software to design a restoration to mate directly with said abutmentincluding the step of correlating said scanned image to a library ofdigital impression coping data; e) creating an output file for additivemanufacturing of the restoration; and f) additively manufacturing therestoration.
 14. The method recited in claim 13 wherein the library ofdigital impression coping data is representative of a plurality ofdigital impression copings corresponding to implant abutments of aplurality of different manufacturers.
 15. The method recited in claim 13wherein step b) comprises the step of producing an oral cavity imagewhich includes at least adjacent and opposing teeth of said patient inrelation to said implant abutment.
 16. The method recited in claim 13wherein step b) comprises using an intra-oral imaging method to scansaid image.
 17. The method recited in claim 13 wherein step b) comprisesusing magnetic resonance imaging (MRI) method to scan said image. 18.The method recited in claim 13 comprising: prior to step a), lockinglyengaging said implant abutment to said implant.
 19. The method recitedin claim 13, further comprising the step of installing the restorationonto the abutment in place of the digital impression coping.